1. Field of the Invention
The present invention relates to a two-component developing agent and a developing method.
2. Description of Related Art
In recent years, performance of an image forming apparatus, especially a color image forming apparatus, has become faster. Accordingly, a problem has been raised that an agitation intensity has become bigger to increase agitation stress to a developing agent in a developing unit, which results in deterioration of toner.
To solve the problem, a specific gravity of a carrier constituted of carrier particles has been lowered, and a magnetic material-dispersed carrier has been proposed, for example. However, in some types of such carriers, carrier particles are easily crushed or deformed when receiving impact.
Meanwhile, there have been studies of decreasing white splotches resulted from an edge effect by putting conductive fine particles in a resin covering layer of a carrier particle to control an electric resistance of the carrier and enhance developability. For example as disclosed in Japanese Patent Laid-Open Publication No. 2011-145497, it has been commonly performed to put carbon black in a resin covering layer of a carrier to raise an electric resistance of the carrier and enhance developability. However, when such a resin covering layer is abraded or exfoliated, resin powder is obtained. The resin powder is colored by carbon black and hence stains images.
In addition, as disclosed in Japanese Patent Laid-Open Publication No. 2011-164230, there also have been studies of decreasing white splotches by putting magnetite in a resin covering layer of a carrier particle. However, magnetite has a high residual magnetization, and thus decreases a fluidity of the carrier.